The Extech LT40 LED Light Meter measures the intensity of illumination in Lux or foot‐candles.
This user guide explains how to operate the Extech LT40 LED light meter, including power on/off, measurement modes, calibration, and data hold functions. It details specifications such as measurement range (up to 400,000 Lux), accuracy, and environmental conditions. Safety and maintenance tips are also provided, including battery replacement and storage guidelines.
| Display | 4-digit LCD (maximum display: 3999) |
|---|---|
| Sensor | Silicon photodiode with spectral response filter and cosine correction |
| Ranges and Resolution | Lux: 399.9, 3999, *39 999, *399 999 |
| Accuracy | ± (3% of reading + 3 digits) up to 500 Lux |
| Operating Temperature | 5 to 40°C (41 to 104°F) |
| Battery Type | 2 x 1.5V AAA batteries |
| Dimensions | 133 x 48 x 23 mm (5.2 x 1.9 x 1") |
The LT40 can measure up to 400,000 Lux (40,000 Fc).
The battery life is approximately 200 hours.